1. Field of the Invention
The present invention relates to a door configured for use on a recreational vehicle. In particular, the present invention relates to a door that may be opened and used as a ramp.
2. Description of Related Art
U.S. Pat. No. 4,398,315 discloses a lip lifting mechanism for a dock board. The dock board includes a ramp that pivots at its rear edge and is connected to a supporting structure. The ramp includes a lip connected to the forward edge of the ramp by a hinge. The ramp is movable between a downwardly hanging pendant position and an extended position. As the ramp moves from an inclined position to a horizontal position, a lip lifting mechanism raises the lip and supports the lip in an extended position. The lip lifting mechanism includes a connection that enables the lip lifting mechanism to yield and move out of the supporting engagement when a force is applied to the lip. In addition, the connection can be manually released in order to allow the lip to move into its pendant position.
U.S. Pat. No. 6,135,532 discloses a recreational vehicle and specialized tail gate and loading ramp. In one embodiment of the invention, the loading ramp assembly comprises first and second loading ramp panels and first, second, third and fourth pairs of cable supports, a cable drive assembly, a load cable and a cable linkage assembly. The first loading ramp panel is secured to the bottom portion of the access opening so as to pivot relative thereto. The second loading ramp panel is secured proximate the second transverse edge of the first panel so as to permit the second panel to pivot relative to the first panel. The cable drive assembly includes a drive cable and a cable translation mechanism. The load cable is secured between a pair of cables secured to the second panel. The cable linkage assembly is arranged to couple movement of the drive cable with movement of the load cable. The linkage assembly and the cable supports are arranged to distribute a uniform load over the load cable. The loading ramp assembly may be arranged in order to permit the first and second loading ramp panels to pivot in opposite directions between an extended position and retracted position, wherein the retracted position is characterized by substantially vertical alignment, and the extended position is characterized by decreasing degree of inclination from the first panel to the second panel.
U.S. Pat. No. 5,598,595 discloses a trailer ramp mechanism. The mechanism is provided for attachment to a pivotable ramp of a trailer in order to assist an operator in manually lifting and lowering of the ramp The mechanism allows the tension of a pair of coil springs positioned on a guide rod to be adjusted. A slotted spring stop permits the lateral positioning of the ramp to accommodate various wheel based equipment to be loaded on the trailer.
U.S. Pat. No. 6,767,171 discloses a recreational vehicle loading and unloading apparatus. The apparatus is configured to load and unload the vehicle from a truck. The apparatus comprises a vehicle receiving ramp and a lifting mechanism that engages with the underside of the ramp. The lifting mechanism is mounted to the rear of the truck and is selectively operable to move the ramp between a lowered inclined position and a raised position parallel to the longitudinal axis of the truck. The ramp is longitudinally mobile in the raised position between a foremost and a rearmost position. A locking mechanism also locks the ramp in the foremost or rearmost position as desired.